Cobalt-Catalyzed Redox-Neutral Sulfonylative Coupling from (Hetero)aryl Boronic Acids, Ammonium Salts and Potassium Metabisulfite

Graphical Cobalt catalysis : An efficient cobalt-catalyzed redox-neutral sulfonylative coupling of boronic acids and ammonium salts to afford (hetero)aryl alkyl sulfones by using potassium metabisulfite has been realized. Various functional sulfones were obtained by using commercially available and air-stable CoCl 2 in combination with phenanthroline ligand. In addition, various carbon based electrophiles, including diaryliodonium salts, heteroaryl halides, and carbonates were compatible. This redox-neutral catalytic transformation proceeds well without additional base and shows broad functional-group tolerance. An efficient cobalt-catalyzed redox-neutral sulfonylative coupling to afford (hetero)aryl alkyl sulfones from boronic acids, ammonium salts and potassium metabisulfite has been realized. Commercially available and air-stable CoCl 2 , in combination with phenanthroline ligand, is sufficient to achieve rapid and high-yielding conversion of the reactants into the corresponding sulfones. This practical transformation proceeds smoothly through C−N bond cleavage under redox-neutral catalytic conditions and shows broad functional-group tolerance. Other carbon based electrophiles, including diaryliodonium salts, heteroaryl halides, and carbonates were compatible. Further transformation of aryl alkyl sulfones then allows conversion into olefins, alkenyl sulfones and halogenated sulfones, respectively, in a one-pot process.